Water tube boiler



Aug. 3, 1965 YUKO FUJI] 3,198,177

WATER TUBE BOILER Filed July 22, 1963 3 Sheets-Sheet 1 INVENTOR yuKo WLL BY WMMW -L p ATTORNEY s Aug. 3, 1965 YUKO FUJI! 3,193,177

WATER TUBE BOILER Filed July 22, 1963 5 Sheets-Sheet 2 Fi 3 7 K 51 M ;1iii? if l7 I5 27 l4 l3 l4 5 22 INVENTOR yu. K0 F 1L3 Li.

BY u) M 43.1 @WZ/ fiw, ATTORNEY:

1965 YUKO FUJll 3,198,177

WATER TUBE BOILER Filed July 22, 1963 3 Sheets-Sheet 5 INVENTOR yuxo Fuu.

BY UDMM M phw ATTORNEY) United States Patent 3,198,177 WATER TUBE BOILERYuko Fujii, Ichilrawashi, Japan, assiguor to Maruzen Iron Works,Limited, Tokyo, Japan, a limited-liability company of Japan Filed July22, 1963, Ser. No. 296,837 2 Claims. (Cl. 122236) The present inventionrelates to water tube boilers, and particularly those of box shape.

The water tube boiler according to the invention essentially comprises amain body of box shape having a main combustion chamber and a convectionchamber, said chambers being formed by partitioning with a vertical walland communicating with each other at their rear ends, and saidconvection chamber being partitioned by vertical bafiles to form azigzag combustion gas passage, a steam drum which is mounted on saidmain body at the top portion of said main combustion chamber, a waterdrum which is embedded in fire proof lining at the bottom portion ofsaid main cumbustion chamber, said drums being connected by a number ofwater tubes, a burner port which is installed on the front Wall of saidmain combustion .chamber and located in a feed air chamber formed on thefront side of said main body, and a number of vertical coiled watertubes which are installed within said convection chamber closelyadjacent to each other and alternating with each other, and successivelyconnected to form long pipe lines, each front end of said pipe linesbeing connected to said steam drum through a circulating pump and eachrear end of said pipe lines being directly connected .to said steamdrum.

The chief features and advantages are as follows:

(1) Said water tube boiler is very compact and elficient, since saidboiler involves the main combustion chamber and the convection chamberwithin the main body of box shape, said chambers being adjacent andcommunicating with each other at their rear ends, and the combustion gaspassing through said chambers is efficiently used to heat the watertubes.

(2) In the main combustion chamber of high temperature of the combustiongas having the steam drum and the water drum, which are connected by anumber of the vertical water tubes, a natural circulation of water iscarried out and said Water is favorably and sufficiently heated.

(3) In the convection chamber the temperature of the combustion gas islower than in the combustion chamber, and in the long pipe linescomposed of a number of the vertical coiled water tubes and in thezigzag combustion gas passage, a forced circulation of Water is carriedout and said water is efiiiciently heated.

The other features and advantages will become apparent from aconsideration of the following description.

In the accompanying drawings:

FIG. 1 is a front view partly in section, of a water tube V boileraccording to the invention;

7 throughout the views.

Referring to FIGS. 1-4, 1 denotes a main body of box shape having acasing 2 provided with fire proof lining 3. Within said main body a maincombustion chamber 4 and a convection chamber 5 are formed bypartitioning with ice a vertical Wall 6, and said chambers communicatewith each other at their rear ends as shown in FIG. 3.

At the top portion of the main combustion chamber 4 a steam drum 7 ismounted on the main body 1, and at the bottom portion of said chamber awater drum 8 is embedded in the lining 3. They are connected by a largenumber of vertical Water tubes 9, which are arranged in parallel alongthe surrounding walls except the front wall of the chamber 4, and by anumber of vertical water tubes 9' which are embedded in the lining 3.Said front wall is conically shaped and provided with a burner port 10,which is located in a feed air chamber 11 formed on the front side ofthe main body 1. In said burner port the injection nozzle of an oilburner 12 is positioned.

The convection chamber 5 is partitioned by a plurality of baflles 13which are alternately arranged upward and downward as shown in FIGS. 3and 4, thereby forming a zigzag combustion gas passage. Installed withinsaid chamber are a large number of vertical rectangularlycoiled watertubes 14 and 14, which are arranged to be closely adjacent and toalternate with each other and successively connected to form two longpipe lines. Each front end of said pipe lines is connected to the outletof a circulating pump 15 which is located in front of the main body 1and driven by a motor 16, and each rear end of said pipe lines isdirectly connected to the steam drum 7, the inlet of said pump beingconnected to the bottom of said steam drum through a feed pipe 17.

Passing through each central part of the coiled water tubes 14 and 14 amotor-driven horizontal pipe 18 is rotatably mounted in the casing. Saidpipe is provided with a number of small holes 19 along its length and isconnected to a steam injector 20 which is secured to the back side ofthe main body 1. At the bottom of the convection chamber 5 a pluralityof drains 21, each of which has an end cover 22, are installed.

Formed above the convection chamber 5 is an air preheating chamber 23which communicates with the former at their front ends and .is providedwith a large number of horizontal combustion gas pipes 24 supported bypartition walls 25, the rear end of said air preheating chambercommunicating with a chimney 26. Adjacent to said chamber and above themain combustion chamber 4 a horizontal air duct 27 is formed whichcommunicates with the combustion gas pipes containing part of thechamber 23 between the partition walls 25, a plurality of verticalbaffles 28 being mounted in the duct 27 and chamber 23 and forming azigzag feed air passage as indicated by arrows 29 in FIG. 5.

The front and rear ends of said air duct communicate with the feed airchamber 11 and a vertical air duct 30, respectively, said vertical airduct being set up behind the main body 1 and connected to an air blower31.

The water tube boiler according to the invention is thus constructed andits operation is as follows:

Water is fed to the steam drum 7, and the vertical Water tubes 9 and 9as well as the water drum 8 are filled with said water. After drivingthe circulating pump 15 by the motor 16, the oil burner 12 is ignited,thereby heating the main combustion chamber 4 up to high temperature ofover 1,300" C. Then said water in the vertical water tubes 9 boils andgoes up to the steam drum 7, where steam separates from the hot water,and comparatively cold water in said steam drum goes down to the waterdrum 8 through the vertical water tubes 9 embedded in the fire prooflining 3, thus a natural circulation of the Water being carried out andheating of the Water being conducted favorably and sufliciently.

The combustion gas produced in the main combustion chamber 4 flows fromits rear end to the convection chamber 5 and flows in a zigzag paththrough it due to the vertical baffles 13 which are alternately arrangedupward and downward, heating the long pipelines com,- posed of a largenumber 'ofthe coiled water tubes 14 and 14' efiiciently, although thegas temperature falls to about 9001,000 C. On the other hand, the waterin said Water tubes boils and is forced to flow to the steam drum ,7,and comparatively coldwater in said steam drum is forcedto flow to'saidWater tubes by the circulating pump 15.

The combustion'gas 'of 300 350 C. passing through the front end of theconvection'charnber 5 goes up to the ,air preheating chamber 23. andpasses through a large number of thejcombustion gas pipes 24 which arehori-,

zontally arranged within said chamber, heating surrounding air whichisfed by the air blower 31 through the vertical air duct 30 and flows ina' zigzag path through thehorizontal airduct'27 as well asthe chamber 23due to the baffles 28. ..Then'said air preheated economically is fed tothe feed air chamber 11, the exhaust-combustion gas, which temperaturefalls to ZOO-250 C., escapes to the chimney 26 from the rear end of theair preheating chamber23. t V

When-the coiled water tubes 14 and 14' are coated with soot, thehorizontal pipe 18 is revolved and steam .is fed to said pipe by thesteam injector 20, then-said steam is emitted from a large numberof thesmall holes 19 in all directions, whereby said {soot adhered to saidwater tubes is blown oif, and the dirty water is discharged 'from thedrains 21, thus therefficient heating of the waterv in saidcoiledwatertubes being steadily maintained.

Without further description it isjthought that the 'fea tures andadvantages of the inventionwill be readily ap- ,parentto those-skilled'in' the art, and it will of course be understood that changes in theform, proportionand -minor details of construction maybe resorted to,without departing from the spirit of theinvention or the scope of theappended claims.

What I claim is:

' .said steam drum, a substantially horizontal partition extending alongthe length of said housing and covering the top of said convectionchamber, means forming an opening between said vertical partition andsaid housing at the end remote from said burner for admitting combustiongases into said -convectionfchamber, a plurality of-transversehorizontally spaced bafiies in said convection chamber, ,alternate-.baflies extending upwardly, from the horizontal partition'defin'inganair preheating chamber,

bottom. of the convection chamber and theremainder extending downwardlyfrom thethorizontal partition, said between itsel'fandthe topwall ofthecasing, aplurality of combustion gas pipes extending longitudinally ofthe casing through said air preheating chamber and having their one endsopening into said convection chamber adjac'ent the end of said casingwith the burner therein and having the other ends opening out of' thecasing at the i other ,end of the air preheating chamber, passage meansbetween said' casing and one end of said air preheating v chamber foradmitting combustion'air into the air preheating chamber, a ductopeningout of the other end of said air preheating vchamber andextendingto saidbur'ner,

and, bafilcs in said air preheating chamber for causing combustionair totravel 'a zigzagpath across said 'combustiongaspipes. r, a l

2. A water tube boiler construction as claimed in claim I v1 furthercomprising a horizontal piperotatably mounted in said casing "andextending through ,said convection -1 A water: tube boilerconstruction,:eomprising asublstantially' right rectangular prismatichousing, a vertical" partition within and; extending along the length ofsaid housing and dividing the housing into a combustion chamber andaconvection chamber, a burner directed into one end of said combustionchamber substantially axially of the longitudinaldimension 10f the;chamber, a steam 'drum along the top of said combustion chamber andextending slightly into said combustion chamber and extending slightlyout of the top surface of'said'housing, said combustion chamber having afireproof lining, a water drum in said lining and extending along thebottom of said combustion chamber, boiler tubes extending from saidwater drum to said steam drum through said combustion chamber, furtherboiler tubes'extending from'said steam drum to said water drum throughthe lining in the side chamber and the centers of the coils of tubestherein, said pipe having a plurality of holes therein spaced along thelength thereof, steam injector means coupled to said pipe, and piperotating means coupled to said pipe for rotating said pipe I 7 jReferences Cited the Examiner UNITED STATES-PATENTS 1,883,293 l1 0/32Iacobus 122-235 1 2,350,202 5/44 Th0mas 165- 95 2,625,917 1/53 Barnes122-250 2,704,534 3/55 Dalin et a1. L- ..122,'4.11X 2,865,342 12/58 Rehm'122-+406 PERCYQL. PATRICK, Primary Examiner. KENNETH w. SPRAGUE,Examiner.

1. A WATER TUBE BOILER CONSTRUCTIOON, COMPRISING A SUBSTANTIALLY RIGHTRECTANGULAR PRISMATIC HOUSING, A VERTICAL PARTITION WITHIN AN EXTENDINGALONG THE LENGTH OF SAID HOUSING AND DIVIDING THE HOUSING INTO ACOMBUSTION CHAMBER AND A CONVECTION CHAMBER, A BURNER DIRECTED INTO ONEEND OF SAID COMBUSTION CHAMBER SUBSTANTIALLY AXIALLY OF THE LONGITUDINALDIMENSION OF THE CHAMBER, A STEAM DRUM ALONG THE TOP OF SAID COMBUSTIONCHAMBER AND EXTENDING SLIGHTLY INTO SAID COMBUSTION CHAMBER ANDEXTENDING SLIGHTLY OUT OF THE TOP SURFACE OF SAID HOUSING, SAIDCOMBUSTION CHAMBER HAVING A FIREPROOF LINING, A WATER DRUM IN SAIDLINING AND EXTENDING ALONG THE BOTTOM OF SAID COMBUSTION CHAMBER, BOILERTUBES EXTENDING FROM SAID WATER DRUM TO SAID STEAM DRUM THROUGH SAIDCOMBUSTION CHAMBER, FURTHER BOILER TUBES EXTENDING FROM SAID STEAM DRUMTO SAID WATER DRUM THROUGH A LINING IN THE SIDE OF SAID COMBUSTIONCHAMBER, A PLURALITY OF COILED TUBES IN SAID CONVECTION CHAMBER, EACHTUBE HAVING A PLURALITY OF SUBSTANTIALLY RECTANGULAR COILS WHICH LIE INSUBSTANTILLY VERTICAL PLANES IN THE CONVENTION CHAMBER, THE ONE ENDS OFSAID COILED TUBES BEING CONNECTED TO ONE END OF SAID STEAM DRUM ANDCIRCULATING PUMP MEANS TO WHICH THE OTHER ENDS OF SAID COIL TUBES ARECONNECTED, SAID CIRCULATING PUMP MEANS BEING CONNECTED TO THE OTHER ENDOF SAID STEAM DRUM, A SUBSTANTIALY HORIZONTAL PARTITION EXTENDING ALONGTHE LENGTH OF SAID HOUSING AND COVERING THE TOP OF SAID CONVECTIONCHAMBER, MEANS FORMING AN OPENING BETWEEN SAID VERTICAL PARTITION ANDSAID HOUSING AT THE END REMOTE FROM SAID BURNER FOR ADMITTING COMBUSTIONGASES INTO SAID CONVECTION CHAMBER, A PLURALITY OF TRANSVERSEHORIZONTALLY SPACED BAFFLES IN SAID CONVECTION CHAMBER, ALTERNATEBAFFLES EXTENDING UPWARDLY FROM THE BOTTOM OF THE CONVECTION CHAMBER ANDTHE REMAINDER EXTENDING DOWNWARDLY FROM THE HORIZONTAL PORTITION, SAIDHORIZONTAL PARTITION DEFINING AN AIR PREHEATING CHAMBER BETWEEN ITSELFAND THE TOP WALL OF THE CASING, A PLURALITY OF COMBUSTION GAS PIPESEXTENDING LONGITUDINALLY OF THE CASTING THROUGH SAID AIR PREHEATINGCHAMBER AND HAVING THEIR ONE ENDS OPENING INTO SAID CONVECTION CHAMBERADJACENT THE END OF SAID CASTING WITH THE BURNER THEREIN AND HAVING THEOTHER END OPENING OUT OF THE CASING AT THE OTHER END OF THE AIRPREHEATING CHAMBER, PASSAGE MEANS BETWEEN SAID CASING OF ONE END OF SAIDAIR PREHEATING CHAMBER FOR ADMITTING COMBUSTION AIR INTO THE AIRPREHEATING CHAMBER, A DUCT OPENING OUT THE OTHER END OF SAID AIRPREHEATING CHAMBER AND EXTENDING TO SAID BURNER, AND BAFFLES IN SAID AIRPREHEATING CHAMBER FOR CAUSING COMBUSION AIR TO TRAVEL A ZIGZAG ACROSSSAID COMBUSTION GAS PIPES.